How coating-on-metal protect steel?

Steel is prone to rusting, a phenomenon that causes the surface to become unsightly and, over time, may contribute to product failure. Corrosion is an electrochemical process that, in the case of steel, oxidizes the iron in the steel and causes it to become thinner over time. This characteristic of steel is very undesirable, both aesthetically and from the aspect of service life. Fortunately coatings can be applied to steel in a very cost-effective manner to confer sufficient corrosion protection so that it can be used for a multitude demanding applications. Coatings-on-metal protects steel in two principle ways: first, like paint, they provide barrier protection, and secondly, they provide galvanic protection in most instances.